cells Flashcards
Organisation from organelles to organisms:
Organelles, cells, tissues, organs, organ systems, organisms.
Give 3 examples of tissues in mammals and describe their role
Muscular - contracts to move
Glandular - produces and secretes chemicals
Epithelial - covers parts of the body.
What is an enzyme and why can they be described as biological catalysts?
Enzymes are proteins that speed up reactions. They can only fit one substrate in the active site, so can only catalyse one reaction.
What do enzymes require?
Optimum temperature and pH
What are the three digestive enzymes and what do they break down?
Amylase - starch into simple sugars
Protease - proteins into amino acids
Lipase - Lipids into glycerol and fatty acids
What is the role of bile?
Neutralises stomach acid so conditions are suitable in the small intestine, and emulsifies fats.
Where is bile produced and stored?
Produced in liver, stored in gallbladder.
Why does fat need to be emulsified with bile?
To increase the surface area of the fats, so lipase can work more effectively.
What is an organ?
A group of different tissues working together to perform a function.
What is the role of the pancreas in digestion?
To produce protease, amylase, and lipase, and release them into the small intestine.
What is the role of the large and small intestine in digestion?
The large absorbs water from food.
The small produces protease, amylase, and lipase, and absorbs digested food into the blood.
Which food test tests for sugars?
What will you see if the test is positive?
Benedict’s Test
Green for not much, red for a lot.
Which food test tests for starch?
What will you see if the test is positive?
Iodine solution
Colour change from orange to blue-black.
Which food test tests for protein?
What will you see if the test is positive?
Biuret Test
Colour change from blue to purple
Which food test tests for lipids?
What will you see if the test is positive?
Sudan III
Red layer in the test tube
Organise these:
Alveoli, Trachea, Bronchioles, Bronchi
Trachea, Bronchi, Bronchioles, Alveoli.
Where does gas exchange happen?
Alveoli.
How are alveoli adapted for gas exchange?
One cell thick
Moist
Surrounded by capillaries
How is the heart’s pace controlled?
A group of cells in the right atrium wall send out electrical signals, causing surrounding cells to contract.
What are stents and statins and how do they reduce cardiovascular disease?
Stents are mesh tubes that hold arteries open.
Statins are drugs that reduce bad cholesterol in the blood.
Give two disadvantages each of stents and statins.
Stents:
- Infection from surgery
- Blood clot near the stent
Statins:
- Have to be taken regularly, long term
- Can have negative, serious side effects
What do phloem tubes transport?
Describe their structure.
Food
Made of elongated cells with small pores in the ends. Transport goes both ways, and is called translocation.
What do xylem tubes transport?
Describe their structure.
Water
They are made of hollow, dead cells. with no gap in between them. The movement of water through and out of the plant is the transpiration stream.
Define transpiration, and state four things that affect it
The loss of water from a plant
Humidity, Air flow, Temperature, Light intensity.
What are the four types of pathogen?
Give an example of each.
Bacteria, Virus, Protist, Fungi
Salmonella, Measles, Rose Black Spot, Malaria.
What causes gonorrhoea?
Bacteria
What can be used to prevent fungal diseases?
Fungicides
What do antibiotics kill, and why is it important to not overuse them?
Bacteria
Bacteria can easily become resistant to antibiotics.
What are the three stages of drug testing?
Preclinical (testing on lab tissues)
Live animals
Clinical trial (human volunteers)
Define drug efficacy
Whether the drug works and produces desired effects.
What are four ways plants use glucose?
- Respiration
- Making Cellulose
- Making amino acids
- Storage - as oils or starch
What is the word equation for photosynthesis?
What affects the rate?
carbon dioxide + water -> glucose + oxygen
Light intensity, CO2 concentration, temperature.
Define and give the word equations for aerobic and anaerobic respiration.
Anaerobic:
- Respiration without oxygen
- Glucose -> Lactic acid
Aerobic:
- Respiration with oxygen
- Glucose + Oxygen = Carbon dioxide + Water
Give the word equation for anaerobic respiration in plants.
Glucose -> ethanol + carbon dioxide
What is an oxygen debt and where is lactic acid oxidised
The amount of oxygen needed to break down lactic acid into glucose, in the liver.
